Enhanced hair straightening system

ABSTRACT

The present enhanced hair straightening system is directed to enhancing the removal of natural curl from hair having a visibly wavy to tight curly configuration using methods and compositions that provide straightened hair which retains desirable sensory tactile properties and hair sheen. The present invention is particularly suited to straightening hair having a curl configuration classified as resistant to conventional hair straightening.

FIELD OF THE INVENTION

This invention relates to removal of the natural curl of hair, and in particular to a hair straightening system, method, and compositions for enhancing the removal of all of the natural curl of hair with minimal loss of desirable hair aesthetics.

BACKGROUND OF THE INVENTION

There is a growing desire and demand globally by persons of ethnic persuasions, other than African descent, who have naturally curly hair ranging from a wavy to tightly curled configuration, for products that can remove substantially all of the natural curl from the hair. In an attempt to describe the visual natural curl configuration of hair, regardless of the ethnicity of the person, one classification system was developed by Andre Walker, a well known hair stylist to celebrities, which has been generally adopted and modified by the trade.

Briefly described, Walker classified Type 1 hair as straight hair (no curl); Type 2 hair as wavy hair (somewhat “S”-shaped, curls); Type 3 hair as being curly (well defined loopy, “S”-shaped wave pattern); and Type 4 hair as kinky, or very tightly curled. Walker also further described sub-types of hair (A, B, C) based upon hair thickness (diameter) from fine, medium, and coarse (super). The Walker classification system for sub-type categories is a subjective system. The trade has further modified this classification system into what is now referred to as a “Global Hair Texture Charting System” and, for convenience, and not by way of limitation, reference will be made herein to the global hair type descriptions.

It is well known that Type 3 and Type 4 hair is very difficult to comb and style. Typically, Type 3 and Type 4 hair has a bulky volume, especially under humid conditions, so maintaining a desirable hair style daily is very difficult. There is an ongoing need for products that can permanently remove substantially all of the natural curl from Type 2-Type 4 hair with minimal loss of desirable hair aesthetics, such as soft tactile feel and visible sheen.

The art of removing the natural curl from naturally curly hair was practiced, in the early days, by applying a pomade to the hair and then straightening the curl by combing the pomade-coated hair, under tension, using a heated metal comb, a process commonly referred to as “pressing.” Although pressing left the hair shiny, silky, the process was cumbersome, and the straightening effect was only temporary. The pomades were cosmetically unaesthetic greases and difficult to remove from the hair. Additionally, the metal combs were heated, either electrically or on a stove, to relatively high temperatures, which posed the risk of burning the unprotected skin and scalp or of singeing the hair. More recently, some progress was made using a hair ironing process employing oily lotions and electrical variable heating devices, known as flat hair irons, and hair irons, some of which are combination hair straightener and curling irons, that can be controllably heated. However, the hair straightening effect is temporary and the curls configuration of hair that is has been temporarily straightened by these procedures reverts to its natural curly or wavy configuration readily on exposure to humidity, or perspiration, and especially upon washing the hair.

Conventional chemical relaxers (hair straighteners) that are formulated to remove substantially all natural curl from the hair are well known in the art and typically contain inorganic or organic bases that form stable, irreversible crosslinks of primarily lanthionine by the action of hydroxide ion. These lanthionizing chemical relaxers generally are strongly alkaline, typically in the range of about pH 12 to about pH 14 and, and typically produce a straight textural configuration that is substantially permanent (i.e., irreversible). It is well known that Type 4 hair is receptive to being successfully straightened with these types of products, whereas Type 2 and Type 3 hair is very resistant.

In some cases, some waves reappear (reversion) in Type 2 and Type 3 hair straightened with lanthionizing chemical relaxers as quickly as the day f the straightening procedure. Customers with Type 3 hair can successfully minimize the overall bulk volume of the curl configuration sufficiently with lanthionizing chemical relaxers, but this type of hair is very resistant to being completely straightened. For effectively removing all the natural curl, the lanthionizing chemical relaxer must be left on the hair for long periods, such as 30 to 45 minutes, which results in unacceptable levels of undesirable hair damage.

An alternative to lanthionization relaxers is a chemical reduction-oxidation relaxer process. Conventional commercial reduction-oxidation processes typically reduce the disulfide bonds in the hair with thiol salts, usually ammonium thioglycolate in a viscous medium at an alkalinity typically in the range of about 9 to about 9.5. The reduced hair is mechanically straightened with combing, and then oxidized with hydrogen peroxide or sodium bromate to restore the disulfide bonds in the new straightened configuration. The straightening effect lasts through about three to four shampooings, but generally provides a less permanent straightening effect than that achieved by lanthionization.

In the period of the late 1990s to early 2000s a Japanese method attempting to avoid conventional lanthionizing chemical relaxer for Type 2 and Type 3 hair was a multiple-step, heat-assisted, reduction-oxidation process. The hair was chemically reduced with an ammonium thioglycolate cream composition for 30-45 minutes. The cream was then rinsed out from the hair and the reduced hair was mechanically straightened with a heated flat iron set at a temperature of about 200° C., and then chemically oxidized with a sodium bromate or hydrogen peroxide lotion. This process, however, was tediously long, taking between four and six hours to complete, and chemical damage was not avoided.

An attempt to achieve permanent hair straightening with some resistance to reversion has been practiced by hairstylists in Brazil using liquid or lotion compositions containing formaldehyde and a blow-drying system (known as “escova progressiva”). This technique is commonly referred to in the trade as a Brazilian Keratin Treatment (BKT) but is popular in many parts of the world.

Formaldehyde is known to form cross-links among protein end groups to create a stable, complex matrix. For example, formaldehyde can form cross-links between amide, amino, and tyrosine groups, S—CH₂—NH cross-links between N-terminal cystine and amine groups, NH—CH₂—NH cross-links between amine groups, and S—CH₂—S (djenkolic acid) cross-links.

In the BKT process, a solution of formaldehyde (1.5 to 5%) is applied to the hair, the hair is then blow-dried and flat ironed while the formaldehyde-containing product is in contact with the hair. After flat-ironing the hair, the hair is rinsed with water and styled with conventional hair styling products. The straightening effect lasts through about two to about three shampooings before having to repeat the straightening process.

A variation of the foregoing procedure has been used in Brazil in which the hair is first swollen with a composition, referred to in the trade as a dilator, having a pH of about 8.5, rinsed, then treated with a lotion called a “no frisse lotion” containing 0.2% formaldehyde, along with a thermal protector lotion containing silicones, and the hair is then blow dried and flat ironed. The hair treated in this manner required repeating the treatment process weekly to progressively to attain some level of discernible straightening over a period of four consecutive weeks. Upon stopping usage of the procedure, however, the configuration of the hair reverts to its original wavy or curly pattern after two to three shampooings.

While hair straightened by the foregoing Brazilian processes was silky, straight and shiny, there are major drawbacks to using formaldehyde-based products due to health and environmental concerns and governmental Regulatory restrictions. The permissible amount of formaldehyde in hair and skin care products in many countries, including Brazil, cannot exceed 0.2% free formaldehyde, making it cosmetically undesirable. Additionally, exposure to formaldehyde solutions can cause contact dermatitis and formaldehyde fumes given off during the blow-drying process raises health concerns to the users and practitioners, because formaldehyde generally is presumed to be a carcinogen. Cross-links produced by formaldehyde are not stable to acid or alkaline hydrolysis, and in aqueous solution, formaldehyde undesirably forms methylene glycol and can react with oxygen to produce formic acid. Thus, formaldehyde is toxicologically unacceptable.

There is an ongoing need and desire, therefore, for cosmetically acceptable compositions and convenient practical methods that remove substantially all of the natural curl from naturally curly hair, especially resistant Type 2 and Type 3 hair, with minimal loss of aesthetically desirable tactile and sheen properties. The present hair straightening system, method and compositions therefor enhance the removal of natural curl from the hair while retaining desirable aesthetic sensory tactile and visual sheen properties.

SUMMARY OF THE INVENTION

The invention is directed to enhancing the removal of the natural curl from hair having a visibly wavy to tight curly configuration using methods and compositions that provide straightened hair which retains a desirable tactile feel and hair sheen. The present invention is particularly suited to straightening resistant hair having a curl configuration classified as Type 2 and Type 3.

Briefly described, the method comprises the following steps (a)-(j), preferably performed sequentially.

(a) Wavy, curly hair is contacted with an alkaline composition comprising a sufficient amount of chemical base to provide alkalinity in the range of at least pH 8.5 to about pH 14, preferably in the range of at least pH 9.5 to about pH 13, more preferably in the range of at least pH 10 to about pH 12 to partially straighten the original configuration of the hair.

(b) The alkaline composition is preferably, but optionally, washed from the partially straightened hair with water.

(c) The partially straightened hair is dried to a substantially dry state.

(d) The so-dried hair is contacted with an acidic composition having acidity of less than about pH 2.5, preferably in the range of pH 1.5 to about pH 2, the acidic composition comprising at least one compound selected from the group consisting of glyoxylic acid, a glyoxylic amide, and a mixture thereof, present in an amount sufficient to further straighten the configuration of the hair.

(e) The so-contacted hair of step (d) is covered with a cap and said contact is maintained for a period of up to about 30 minutes, preferably with heating.

(f) The cap is removed, and the hair is dried, preferably with heating, to a substantially dried state.

(g) The substantially dried straightened hair is pressed with a heated iron, preferably with multiple passes of the iron to mechanically increase straightening.

(h) The pressed, straightened hair is washed with water, and optionally the washed hair is contacted with a hair conditioning composition comprising an oxidizing agent for a time period sufficient to condition the hair, and optionally, the conditioned hair is washed with water.

(i) After step (h), the hair is blow-dried, optionally with a thermal protectant composition on the hair.

(j) The blow-dried hair is pressed with a heated iron, optionally with a hair conditioning composition on the hair.

The chemical base in the alkaline composition preferably comprises at least one compound selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxides, an organic amine, and salts thereof. Preferably at least one alkali metal hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and the like. Preferably, the alkaline metal hydroxide is calcium hydroxide. Preferably at least one organic amine is selected from the group consisting of guanidine, guanidine hydroxide, and C₁-C₆ alkanolamine. Preferably at least one alkaline salt is selected from the group consisting of sodium carbonate, and sodium phosphate.

Preferably the alkaline composition remains in contact with the hair for a period sufficient to partially straighten the hair within a period of about 10 to not more than about 30 minutes. Most preferably, the amount of chemical base preferably is sufficient to effectively partially straighten the hair and maintain a pH of at least 9.5, preferably greater than pH 10, during the time the alkaline composition is in contact with the hair.

A preferred acidic composition comprises glyoxylic acid, and/or a glyoxylamide selected from the group consisting of N-glyoxylcarbocysteine, N-glyoxylderivatives of keratin amino acids and mixtures thereof.

Type 2 to Type 4 hair straightened by the enhanced hair straightening system of this invention was surprisingly soft, silky, and shiny.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a digital image of wavy hair illustrating the classification of hair waviness calculated from the undulated relationship of A and W in the sinusoidal-like, “S”-shaped wave as described herein in the Materials and Methods section.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The singular terms “a”, “an”, and “the”, as used in the specification and the appended claims include plural referents unless the context clearly dictates otherwise. The antecedent term “about” applied to a recited range or value denotes an approximation within the deviation in the range or value known or expected in the art from the measurements method.

The term “permanent straightening” means that the natural curl of the hair has been removed and that the resulting straight configuration effectively resists reversion (i.e., resumption of a curly pattern) on being subjected to more than one washing, preferably at least four washings, and more preferably at least eight washings or lasts until the scalp hair grows sufficiently to visibly warrant another hair straightening procedure. The terms “washed” and “washing” includes rinsing with water.

The term “substantially dry” with reference to hair means that the hair feels dry to the touch.

The term “heating”, and “elevated temperature”, as used herein with reference to hair, refers to the use of a heating device commonly used by consumers and salon professionals for hair styling procedures, such as an electric hand-held dryer; a domed/hooded hair dryer, a hair steamer, heating cap, or an electrical flat heating iron. Hand-held hair dryers are conventionally used to “blow dry” hair, preferably using an ambient heat setting temperature in the range of about 100° C. to about 108° C., more preferably in the range of about 105° C. to about 106° C. Commercial electric flat hair irons are available having variable heat settings, and preferably are ceramic. Useful flat irons can be heated to platen temperatures in the range of about 100° C. to about 230° C., more preferably in the range of about 180° C. to about 200° C. Commercial hair steamers are available having variable steam mist heating settings and fitted with steam bonnets and water reservoirs. Hair steamers are conventionally used to condition the hair and/or scalp, typically set at a medium setting for generating a moderate moist mist temperature of about 49° C. Hair steaming is typically performed for about 8 minutes at a medium setting followed by a cool down period of about 2 minutes or, at a low setting for generating a low mist and moderate temperature for a period of about 10 minutes followed by a cool down period of about 2 minutes.

The term “hair conditioning” is used in its conventionally understood meaning to include the desirable enhancement of the physical sensory properties (softness, silkiness, smoothness, and the like), mechanical styling (ease of combing, static flyaway, and the like), and visual appearance of the hair (hair color, sheen, and the like) relative to that before the conditioning procedure. The terms “relax” and “straighten,” and grammatical variations thereof with reference to hair are used interchangeably herein to mean that the natural curl of the hair has been chemically straightened with a alkaline composition having a pH of at least 10.

The term “cosmetically acceptable vehicle” means that the composition comprises ingredients commonly recognized in the art as suitable for compositions, such as cosmetics, cosmeceuticals, and the like, that are topically applied to human hair and skin. Cosmetically acceptable vehicles for compositions useful in the hair straightening system of this invention are illustrated in the Examples below, without being limited thereto.

Ingredients that can be employed in the hair straightening and hair conditioning compositions and system discussed herein are referred to by their commonly used chemical or trade names or by the international nomenclature commonly referred to as INCI name given them in any edition of the International Cosmetic Ingredient Dictionary and Handbook, (hereafter INCI Dictionary), such as found in Volumes 1-3, of the Seventh Edition (1997) or Eighth Edition (2000) or Ninth Edition (2002), all published by the Cosmetic, Toiletry, and Fragrance Association, Washington D.C. (now Personal Care Products Council). Numerous commercial suppliers of materials listed by INCI name, trade name, or both, can be found in any edition of the INCI Dictionary and in numerous commercial trade publications, including but not limited to, the 2001 Cosmetic Bench Reference edition of COSMETICS & TOILETRIES®, 115 (13), or the Cosmetic Bench Reference 2004, both published by Allured Publishing Corporation, Carol Stream, Ill. (2001), and the 2001 McCutcheon's Directories, Volume 1: Emulsifiers & Detergents and Volume 2: Functional Materials, published by McCutcheon's Division, The Manufacturing Confectioner Publishing Co., Glen Rock, N.J. (2001); the relevant disclosures of each of the foregoing publications being incorporated herein by reference.

The term “cosmetic adjuvant” includes cosmetically useful product finishing and promotional additives, well known and conventionally used in the cosmetic arts to maintain the physical stability of a composition during storage (shelf life), and the visible aesthetic appearance of a composition during storage and during the use of the composition. Cosmetic adjuvants that maintain the stability of products typically include a metal-ion chelating agent, an antioxidizing agent, a preservative, an emulsifying agent, a perfume solubilizer, and the like, but are not limited thereto. Cosmetic adjuvants, sometimes called promotional ingredients, aid in enhancing the aesthetics and marketing appeal of the product and include, without limitation, a product colorant, a fragrance, and the like.

The chemical base in the alkaline compositions preferably comprises at least one compound selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, an organic amine, and salts thereof. Preferred alkali metal hydroxides are selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, and the like. Sodium hydroxide is preferred. Alkaline earth metal hydroxide is preferably calcium hydroxide. Organic amines are preferably selected from the group consisting of guanidine, guanidine hydroxide, and C₁-C₆ alkalolamine. Exemplary C₁-C₆ alkanolamines include monoethanolamine, diethanolamine, triethanolamine, di-isopropylamine, and the like. Triethanolamine is preferred. Preferred alkaline salts are selected from the group consisting of sodium carbonate and sodium phosphate.

A useful concentration of sodium hydroxide is in the range of about 0.05 to about 1.5, preferably in the range of about 0.1 to about 1, active weight percent based on the weight of the composition. A useful concentration of triethanolamine is in the range of about 0.1 to about 1.5, preferably in the range of about 0.2 to about 1 active weight percent, based on the weight of the composition.

Guanidine hydroxide is preferably prepared just before use by admixing a composition comprising calcium hydroxide with a composition comprising guanidine carbonate. For normal to resistant hair, about 140 grams of a composition comprising calcium hydroxide, in a range of about 5.5 to about 7.5 active weight percent, can be admixed with about 10 to about 20 grams of a composition, typically called an “activator,” comprising about 27.2 active weight percent of guanidine carbonate.

Acidic compositions employed in the method of this invention preferably comprise at least one organic compound selected from the group consisting of glyoxylic acid, a glyoxylic amide, and a mixture thereof, in a cosmetically acceptable vehicle having an acidic pH of less than about pH 2.5, preferably in the range of about pH 1.5 to about pH 2. The amount of organic compound is preferably in the range of about 5 to about 25, more preferably in the range of about 10 to about 20, most preferably in the range of about 15 to about 18 active weight percent, based on the total weight of the acidic composition.

Glyoxylic acid, also called oxoacetic acid or oxoethanoic acid, is an organic compound having a molecular formula of C₂H₂O₃, a melting point of 80° C., and a boiling point of 111° C. It is usually described by the chemical formula OCHCO₂H. Although glyoxylic acid is an aldehydic acid, the aldehyde functional group is not observed in solution or as a solid. Thus, glyoxylic acid, like aldehydes with electron-withdrawing substituents, reportedly exists in what is described as the “monohydrate” form, (HO)₂CHCO₂H, and this diol exists in equilibrium with the dimeric hemiacetal in solution. A preferred amount of glyoxylic acid is in the range of about 5 to about 20 active weight percent, more preferably in the range of about 10 to about 15 active weight percent, based on the total weight of the finished composition.

Glyoxylic amides are preferably selected from the group consisting of N-glyoxylcarbocysteine, N-glyoxylderivatives of keratin amino acids and mixtures thereof. A mixture of N-glyoxylcarbocysteine, N-glyoxylderivatives of keratin amino acids is commercially available from Polytechno Indústrias Químicas Ltda under the trade name PROLISS 100, identified as a mixture of oxoacetamidocarbocysteine and oxoacetamido amino acids derived from keratin (hydrolyzed keratin). According to the manufacturer, the PROLISS 100 organic compound does not liberate formaldehyde even at elevated temperatures of up to 200° C. A preferred amount of glyoxylamide is in the range of about 5 to about 25 active weight percent, more preferably in the range of about 10 to about 20 active weight percent, most preferably in the range of about 15 to about 18 weight percent, based on the total weight of the finished composition.

Those skilled in the formulation arts can readily determine the amounts of chemical base in the alkaline compositions, and the glyoxylic acid and glyoxlic amides to be used in the acidic compositions by the amount of curl removal desired for the hair type. The compositions can be prepared and used in the form of aqueous liquids, or formulated as emulsions by techniques known in the art. A preferred composition is in the form of a cosmetically acceptable aqueous emulsion vehicle comprising emulsifiers, cationic polymers, hair conditioning agents, hair protective lubricants, and the like.

In the practice of the method of this invention, reference is made to the type of natural curl in the hair, described by its Global Type and Sub-type classification as set out in Table 1 for convenience without being limited thereto.

TABLE 1 GLOBAL HAIR TYPE CLASSIFICATION STRAIGHT TYPE-1 WAVY TYPE-2 Attributes 1A 1B 1C 2A 2B 2C Texture Fine Medium Coarse Fine/Thin Medium Coarse Wave Pattern-Dry None None None Wavy Wavy Wavy S-Pattern S-Pattern Pronounced, Well-Defined S-Pattern Wave Pattern-Wet Straight Straight Straight Straight Straight Wavy Stylability/ Low Medium Medium Easily Slightly Easily Manageability straightened resistant to straightened or or curled styling curled Body Low High High Medium Medium Medium Elasticity/ Low/ Medium/ High/ Medium/ Medium/ Medium/ Strength Strong Strong Very Strong Strong Strong Strong Frizz Tendencies Low Low Low Medium Medium Medium to Easy Shine High High High Less Than Less Than Less Than Gloss Type-1 Type-1 Type-1 Scalp & Hair Oily Oily Oily Normal Normal Normal Dryness/ Oiliness CURLY - TYPE-3 TIGHTLY CURLED - TYPE-4 Attributes 3A 3B 3C 4A 4B 4C Texture Thin Medium Coarse Fine Medium/ Coarse Coarse Wave Pattern- Soft, Medium Tight Tight Curls Kinky/ Very Kinky/ Dry naturally Loopy S- Loopy S-Curl when Coils when Coils when loose, Curl* stretched stretched make stretched make loopy S- make an S- a Z-shape a Z-shape Curl shape Wave Pattern- Wavy Wavier Wavier Coiled Tighter Coil Very Tight Coil Wet than 3A than 3B than 4A Stylability/ Low/ Low/ Low/ Very Low Very Low/ Very Low/ Manageability Difficult Difficult Difficult Difficult Difficult Body High High High Very High Very High Very High Elasticity/ High/ High/ High/ Poor/ Poor/ Poor/ Strength Strong Strong Strong Fragile Fragile Fragile Frizz High High High High High High Tendencies Shine Dull Dull Dull Low L:ow Low Scalp & Hair Normal Somewhat Somewhat Dry Very Dry Very Dry Dryness/ Dry Dry Oiliness *Ringlets to tight corkscrew configuration

Wavy, curly and very curly Type 2 to Type 4 hair is always difficult to comb in both its wet and dry state and is always difficult to style. Variations in weather and climate, in particular, affect this type of hair making it even more difficult to style as humidity increases. Type 4 hair, in particular, also is fragile and loses it tensile strength significantly (up to as much as 35 to 52%) upon being straightened with conventional alkaline relaxers containing sodium hydroxide or guanidine hydroxide and the feel and shine of the straightened hair is also significantly compromised (the straightened hair but feels rough and is dulled). Type 2 and Type 3 hair tends to be very resistant to alkaline hair straighteners containing sodium hydroxide or guanidine hydroxide as the chemical base. This straightening effect on these hair types also tends to revert immediately to being somewhat wavy or slightly curly right after receiving these alkaline hair straightening procedures, especially under humid conditions.

Briefly described, in the method of this invention, the naturally curly hair is first partially straightened with an alkaline composition comprising a chemical base at a pH of at least 8.5, preferably at least about 9.5, more preferably at least about 10, then further straightened with an acidic composition comprising at least one organic compound selected from the group consisting of glyoxylic acid, a glyoxylic amide, and a mixture thereof, preferably at an elevated temperature, followed by further mechanically straightening the hair by multiple pressings with a heated flat iron. Type 2-4 hair is effectively straightened, loss of tensile strength is minimized, and the hair is desirably soft, silky to the touch, and has a luxurious sheen.

In one aspect, the efficacy of the hair straightening system of this invention was evaluated by determining retention of the tensile strength of the hair employing an Intermittent Stress Relaxation (ISR) method, described in the Materials and Methods section below. In another aspect, the efficacy of the hair straightening system was assessed by determining the hair waviness from digital images taken of the hair before and after receiving a procedure, also as described in the Materials and Methods section.

In one particularly preferred embodiment of the method of this invention, the naturally curly hair is first partially straightened for about 10 minutes, preferably to a visibly looser, straighter configuration with an alkaline composition comprising a sufficient amount of chemical base to maintain a pH of at least 9.5, preferably of at least 10, during the partial straightening process. After washing the alkaline composition from the hair with water and drying the washed hair, preferably under a hooded salon hair dryer, to a substantially dry state, the so-dried hair is further straightened by contacting the hair with an acidic composition preferably having a pH in the range of about 1.5 to about 2, and comprising at least one organic compound selected from the group consisting of glyoxylic acid, a glyoxylic amide, and a mixture thereof. The organic compound is preferably present in an amount sufficient to further straighten the configuration of the hair. Preferably, the so-contacted hair is covered with a cap (plastic or metallic foil) and the contact maintained for a period of up to about 30 minutes, preferably heated using a hair steamer or hair dryer.

The further straightened hair is then preferably blown dry to a substantially dried state, using a hand-held electric hair dryer while brushing the hair with a round or flat brush. Alternatively, the further straightened hair is set on rollers having a wide diameter of at least about 3.8 centimeters (about 1.5 inches) and dried under an electric hooded salon dryer. After drying the straightened hair, thin tress sections of the hair are selected and pressed with multiple passes of a heated flat iron, set a temperature in the range of about 180° C. to about 230° C. to further mechanically straighten the configuration of the hair. After pressing, the hair is cooled at ambient room temperature for about 5 minutes, and then rinsed with water with remove any residual acidic composition from the hair.

In another preferred embodiment, the method further includes conditioning the washed, pressed straightened hair with a hair conditioning composition comprising an oxidizing agent for a time period sufficient to condition the hair and remove any unwanted residual chemical odor remaining thereon. Preferably, but optionally, the oxidant conditioner is washed from the air with water.

The oxidant hair conditioning composition preferably contains an oxidizing agent selected from hydrogen peroxide, sodium bromate, and the like. The amount of hydrogen peroxide preferably is in the range of about 1 to about 10 active weight percent, more preferably in the range of about 2.5 to about 3 active weight percent, based on the total weight of the hair conditioning composition. The amount of sodium bromate preferably is in the range of about 1 to about 6 active weight percent, more preferably in the range of about 4 to about 5 active weight percent, based on the total weight of the hair conditioning composition. The oxidant hair conditioning composition improves the olefactory characteristics of chemically straightened hair by effectively eliminating any undesirable residual chemical odors sometimes attendant to heat-assisted, chemical hair straightening processes. The oxidant hair conditioning composition is preferably rinsed from the hair to minimize lightening of the natural hair color, or alternatively, can remain on the hair if the user wishes to intentionally lighten or highlight the natural hair color.

The wet conditioned hair can be blotted with a towel, and the coiffure finished as is practiced in the art, by typically applying a thermal protectant hair conditioning composition to the towel-blotted hair and blow-drying the hair using a flat brush, and preferably, but optionally, subsequently applying a hair conditioning sheen product to the hair and pressing selected large tress sections of the hair to a final, Type-1 like, straight style with a flat iron set at a temperature of about 180° C.-200° C.

Hair straightening compositions of this invention for use in the enhanced hair straightening system and method are preferably provided in kits in packaged form, together with instructional indicia for use. A preferred kit embodiment includes at least one acidic composition, and preferably an alkaline composition. The kit may contain one or more implements for performing a hair straightening procedure, i.e., disposable gloves, brush, comb, a hand-held blow dryer, a flat hair iron, and the like. The kit components preferably are contained in an outer package. The outer package can be a box or carton or shrink wrap, and preferably has instructional indicia printed thereon or visible therethrough.

Useful instructional indicia can be printed media, aural media, visual aids, electronic media or a combination thereof, which instruct the user on the use of the hair straightening product in the hair straightening system. Printed media include, but are not limited to, labels attached to, or imprinted on, the components of the kit, package inserts, pamphlets, books, flyers, and the like. Aural media include, but are not limited to, tape recordings, audio compact disks, records, and the like. Visual aids include, but are not limited, to photographs, slides, movies, videos, DVDs, and the like. Electronic media includes all forms of electronic data storage media, such as, but not limited to, diskettes, interactive CD-ROMs, interactive DVDs, and the like.

While the mechanism of the hair straightening system is not fully understood, and without being limited thereto, it is believed that the hair is first partially straightened by being lanthionized by the alkaline chemical base and then restructured by the acidic composition further introducing stable crosslinks to the lanthionized hair, augmented by elevated temperatures and mechanical heated straightening to enhance hair straightening while surprisingly retaining the desirable aesthetic properties of the hair.

The following non-limiting examples are provided to further illustrate the invention.

Materials and Methods

In the following examples the following materials and methods were used, unless otherwise indicated, to assess the efficacy of the enhanced hair straightening system of this invention.

I. Intermittent Stress Relaxation Method (ISR)

One preferred method of evaluating the elastic tensile strength of wet hair is referred to as the “Intermittent Stress Relaxation (ISR) Method” using a Dynamic Mechanical Analyzer (e.g., TA Instruments, Model Q800) equipped with a hair-fiber anchoring assembly that can be submerged in water. In the ISR Method an individual hair fiber (gauge length about 14.82 millimeters (mm) in length) is clamped at two opposing portions in the fiber anchoring assembly, which is then submerged in water. The length of the submerged hair fiber is then stretched in water to a constant strain of about 0.5% of its length (i.e., an elongation of about 0.07 mm to a total length of about 14.89 mm) for about 0.1 minute, and then allowed to relax by removing the strain for about 0.9 minutes, and this cycle of intermittent stress strain and relaxation is repeated for a total of about 10 cycles.

The area of the hair fiber is measured using a Beta LaserMike micrometer (Beta LaserMike, USA). The average area is recorded as (x+y)/2 where x is the minor axis and y is the major axis. The amount of stress (in grams/denier fiber) for each cycle of hair fiber is measured and recorded before and after receiving a hair straightening procedure. The ratio (index) of the stress of the hair before receiving the procedure relative to the stress of the hair after the procedure is calculated and the change in the ratio is judged as indicative of loss, or protection from loss, in tensile strength. An index value of 1=no change in hair tensile strength, an index value of less than 1 indicates a loss (weakening) in tensile strength, and an index value of greater than 1 indicates an increase (strengthening) in tensile strength. The ISR is evaluated for randomly sampled ten hair fibers by measuring the ISR of the hair fiber before and after a hair straightening and then calculating the ISR Index in this manner for each of the fibers.

Measuring the elasticity of wet hair, when stretched in the range of about 0.5 to about 1 percent of its length, is judged as simulating the range of strain applied during a conventional hair grooming process, such as combing, brushing, styling and setting of the hair.

II. Hair Straightening Method

The following method was used in salon studies, unless otherwise indicated.

1. A digital photograph is taken of the front and back view of the subject's dry hair before starting the procedure. The subject's hair type is assessed and recorded.

2. The hair is then wet with water to determine and classify the degree of curl pattern, and a digital picture of the back of the hair is taken to serve as a control.

3. The wet hair is then dried to the touch with a hand-held dryer or a hood dryer. Hair dried to the touch is referred to herein as substantially dried hair and is generally estimated to be about 80 to 90 percent dry.

4. An Alkaline Composition of this invention, as identified in the following examples, is applied to, and distributed through, the hair. A sufficient amount of the composition is applied to thoroughly coat the fibers from the root to the end portions of the hair. The amount of the Alkaline Composition applied overall to the head of hair typically is in the range of about 190 to about 290 grams, depending on the length and volume density of the hair. The Alkaline Composition is left in contact with the hair for a period in the range of about 10 to not more than about 40 minutes or a period sufficient to partially straighten the hair. The hair is checked periodically and is judged as being sufficiently partially straightened when the curl lays flat and straight. The partially straightened hair is then water rinsed. (Water rinsing can be dispensed with, if desired, where an Alkaline Composition, such as illustrated in Examples 2, and 5 is employed).

5. The water-rinsed hair is substantially dried, preferably under a hooded dryer.

6. An Acidic composition of this invention, as identified in the following Examples, is applied to, and distributed through the hair, by parting the hair into narrow tress sections and brushing the composition onto each selected tress section. The amount of Acidic Composition applied to the overall head of hair is typically in the range of about 60 to about 90 grams. Where side by side (half-head) comparisons are desired, the hair is first sectioned from front to back and about 30 to about 45 g of Acidic Composition is applied per side.

7. The hair preferably is covered with aluminum foil to provide a metal cap, and then steamed for a period of about 15 to about 30 minutes under a commercial hair steamer set at a medium steam mist heat setting (about 49° C.). A commercial hair steamer, such as available from YCC Products, Inc., is useful. If a hair steamer is unavailable, a plastic cap and a conventional hair dryer can be used. Alternatively, the cap-covered hair can be maintained at ambient room temperature.

8. The cap is removed from the hair.

9. The hair is then blow-dried using a hand-held hair dryer and a brush (round or flat) or the fingers. Alternatively, the hair is roller-set and dried as described in step 10.

10. If roller setting is chosen after step 8, the hair is wound on rollers having a medium large diameter of about 3.8 cm (1.5 inches) and then dried under a hooded hair dryer.

11. When the hair is substantially dry, the rollers are removed and the hair is pressed with multiple passes of a heated Flat Iron set at a high heat setting (about 180° C. to about 230° C.). Typically the hair is parted into thin, narrow tress sections and about seven passes of the heated Flat iron per selected tress section is judged sufficient to further mechanically straighten the hair.

12. The pressed hair is then cooled for about 5 minutes.

13. The cooled hair is then rinsed with water to remove residual Acidic Composition from the straightened hair.

14. If desired, a hair conditioning composition comprising an oxidizing agent is applied to the pressed hair, distributed therethrough and left in contact with the hair for about 15 minutes. The amount of the hair conditioning composition applied typically is in the range of about 30 to about 60 grams. The hair is then water rinsed and excess moisture is blotted with a towel.

15. The hair is blow-dried using a flat brush, preferably with a thermal protectant composition, such as KERACARE® Thermal Protector (Avlon Industries, Inc.), applied to the hair.

16. The hair pressed with multiple passes of a heated Flat Iron at a high heat setting (about 180° C. to about 230° C.) through wide tresses sections, preferably with a conditioning styling composition, such as KERACARE®Silken Seal Liquid Sheen (Avlon Industries, Inc.) is applied to the hair.

If the subject is satisfied with the level of hair straightening achieved after step 13, one or more of steps 14, 15, and 16 can be omitted.

III. Digital Image Classification of Hair Waviness

The efficacy of the hair straightening system of this invention can be evaluated at any step of the procedure described in Method II by digitally classifying the wave configuration of the hair before and after receiving a procedure and by calculating the change in waviness as described below.

1. Categorize the waviness of the hair by taking a digital photograph of the back view of the subject's head, with a ruler positioned alongside the hair to record the length of the hair being imaged. The ruler is preferably scaled in centimeters and provides a guide for generally categorizing the same length of hair when a subsequent digital photograph is taken.

2. Classify the waviness of the photographed image of the hair as illustrated in FIG. 1 by measuring the distance (W) between the peaks and the depth (A) of the valley of at least one sinusoidal-like, undulating “S”-shaped curve and calculating the waviness factor (V) using the following equation: V=2A/W. The waviness factor calculated for the subject's hair before receiving any straightening procedures (step 1 or 2 of Method II) is referred to as Vo, where “o” represents the original waviness of the subject's hair normalized to 100%.

3. Repeat steps 1 and 2 at any given step of Method II and calculate the waviness factor. The waviness factor calculated after any given step of Method II is referred to as Vsn, where “sn” represents the step number at which the digital image was taken. The waviness factor is normalized relative to Vo and Vsn, and represents the residual waviness of the hair at that point. For example, a Vsn of 48 represents a total hair waviness of 48% for that subject.

4. The efficacy of the hair straightening procedure at any step of the procedure is determined by calculating the change in the ratio of Vo to Vsn, by using the equation Vo−Vsn. For example, the change from a Vo of 100 to a Vsn of 48 represents a reduction in waviness (i.e., the straightening efficacy) of 52%.

The straightening efficacy can be determined at any step in the hair straightening procedure, and on wet or dry hair, as desired.

The following examples illustrate Acidic and Alkaline Compositions and hair conditioning compositions comprising an oxidizing agent suitable for use in the method of this invention, and are not intended to be limiting. The ingredients are identified by their trade name, or common name or the INCI name assigned by the supplier. The amounts are listed either as active weight percent, or as weight percent as is (i.e., added as supplied by the manufacturer), based on the total weight of the finished composition, unless indicated otherwise. The term “q.s.” with reference to the amount of ingredient is commonly understood in the art to mean “quantity sufficient”, and is generally readily determined by persons skilled in the formulation arts. Likewise, those skilled in the art understand that the term “deionized water to 100%” means the amount of water added is sufficient to complete the formulation to the final finished weight, (i.e., in % or as parts by weight) and is readily determined by the skilled formulator.

Example 1 Alkaline Compositions

A B Weight Weight Ingredients Percent Percent Trade/Common/INCI/Name Active Active White Petrolatum 9 9 Mineral Oil 12 12 Cetearyl Alcohol (and) Dicetyl Phosphate 7.5 7.5 (and) Ceteth-10 Phosphate Ceteth-10 3 3 Ceteth-2 0.5 0.5 Polysorbate-60 0.5 0.5 Shea Butter 0.05 0.05 Cocoa Butter 0.05 0.05 Simethicone 0.02 0.02 Green Tea 0.01 0.01 Calendula Petals 0.01 0.01 Propylene Glycol 2 2 Honey 0.01 0.01 Polyvinyl Alcohol 1 1 Fragrance q.s. q.s. Ethylene Urea — 1.7 Sodium Hydroxide 1 0.5 Betz Polymer 1195 0.4 1 Aloe Vera Powder 0.025 0.03 Deionized Water to 100% q.s. q.s. pH 12.8 11.8 q.s. = quantity sufficient

Example 2 Alkaline Compositions

B E F G Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name Active Active Active Active Quaternium-80 0.25 0.25 0.25 0.25 Polysorbate 20 0.5 0.5 0.5 0.5 Simethicone — — — 0.02 Polyvinyl Alcohol 1 — — — Fragrance 0.1 0.05 0.05 0.2 Hydrolyzed Keratin — — — 0.1 Triethanolamine (99%) 1 0.69 0.36 0.6 Keratin (and) Hydrolyzed Keratin 0.1 0.1 0.1 — Preservative q.s. q.s. q.s. q.s. Deionized Water to 100% q.s. q.s. q.s. q.s. pH at 25° C. 9.5 9.5 9.4 8.5-9.5 q.s. = quantity sufficient

Example 3 Hair Conditioners

This example illustrates hair conditioning compositions comprising an oxidizing agent.

B C D Weight Weight Weight Ingredients Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is Versene 220 0.2 0.2 0.2 Soyethyl Morpholinium 0.5 0.5 0.5 Ethosulfate Behentrimonium Methosulfate 2 2 3.7 (and) Cetearyl Alcohol Ceteth-2 1.3 1.3 2.5 Fatty Alcohol - TA 1618F 5 7 5 Ceteareth-20 2.2 3 2.2 Sodium Stearoamphoacetate 2 2 2 Sodium Bromate CG 7 7 7 Disodium Phosphate Anhydrous 0.6 0.6 0.6 Deionized Water to 100% q.s. q.s q.s. pH 7 7 7.1

Example 4 Alkaline Composition

This example illustrates the use of an Alkaline Composition where the chemical base is guanidine hydroxide. The Alkaline Composition is prepared immediately before using by mixing together about 140 grams of a commercial creme relaxer (AFFIRM Moisture Plus Creme Relaxer Prime), comprising about 8.75% calcium hydroxide, with about 14 grams of a commercial liquid aqueous activator (AFFIRM Liquid Activator Prime), comprising about 27.2% guanidine carbonate.

One subject having previously colored, Type 3B hair received enhanced hair straightening using a half-head comparison in a salon study. The hair straightening procedure of Method II described above was generally followed using the freshly prepared Alkaline Composition, leaving it in contact with the hair for about 18 minutes to partially straighten the tight curls, and then thoroughly rinsed from the hair. The half-head procedure of step 6 was performed by applying the Acidic Composition of Example 8AG to the hair on one side and the Acidic Composition of Example 11BC to the hair on the opposite side. Each composition comprised about 15 active weight percent glyoxylic amide. The Acidic Composition was left in contact with the hair about 30 minutes, steam heated, blown-dry and flat ironed as described in steps 7-13.

The straightened hair was conditioned in step 14 with a hair conditioner containing about 2% hydrogen peroxide. The oxidant hair conditioner was prepared by admixing one part by weight of 6% hydrogen peroxide liquid into two parts by weight of a commercial hair conditioner (AFFIRM 5 in 1 Reconstructive Conditioner, Avlon Industries, Inc.).

The straightening achieved on this Type 3B hair with the Alkaline Composition was judged to be about 76%. Overall, the straightening of the hair by the Acidic Compositions was judged to be enhanced to about 79%, based on the appearance of the wet hair and enhanced to about 98%, based on the appearance of the dry hair. The straightened hair was very silky and soft in feel, was very shiny and any undesirable residual chemical odor on the hair was minimized.

Example 5 Alkaline Compositions

D H Ingredients Weight % Weight % Trade/Common/INC/Name As is As is Quaternium-80 0.25 — Polyquaternium-6 — 0.5 Polysorbate-20 0.5 0.5 Fragrance 0.05 0.05 Sodium Carbonate 0.003 — Keratin (and) Hydrolyzed Keratin 0.1 — Sodium Hydroxide (50%) — 0.5 Preservative 0.1 — Potassium Sorbate 0.1 — Deionized Water to 100% q.s. q.s. pH at 25° C. 9.3 12.1

Example 6 Acidic Compositions

M O Q R Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is As Is Citric Acid 0.05 0.05 0.05 0.05 Ceteth-2 0.9 0.9 0.45 0.45 Glyceryl Stearate (and) 0.1 0.1 0.05 0.05 PEG-100 Stearate Argan Oil 0.5 2 1 1 Dimethyl Stearamide 0.5 0.5 0.25 0.5 Behentrimonium Methosulfate 0.2 0.2 0.2 — (and) Cetearyl Alcohol Cetyl Alcohol 0.134 0.134 0.134 — Keratin (and) 0.1 0.1 0.1 0.1 Hydrolyzed Keratin Cyclomethicone 2 2 2 5 Perfluorononyl Dimethicone 0.5 0.5 0.5 — Cetyl Dimethicone 0.25 0.25 0.25 — Fragrance 0.2 0.2 0.05 0.05 Preservative 0.1 0.1 0.05 0.05 Potassium Sorbate 0.1 0.1 — — Proliss 100 (50%) 30 30 30 30 Deionized Water to 100% q.s. q.s. q.s. q.s.

Example 7 Acidic Compositions

U Y Z AA Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is As Is Citric Acid 0.05 0.05 0.05 0.05 Ceteth-2 0.45 0.45 0.45 0.45 Glyceryl Stearate (and) 0.05 0.05 0.05 0.05 PEG-100 Stearate Argan Oil 0.75 0.75 0.75 0.75 Dimethyl Stearamide 0.25 0.25 0.25 0.25 Behentrimonium Methosulfate 0.2 0.2 0.2 0.2 (and) Cetearyl Alcohol Cetyl Alcohol 0.13 0.13 0.13 0.13 Hydrolyzed Keratin 0.1 0.1 0.1 0.1 Cyclomethicone 5 10 10 12.5 Perfluorononyl Dimethicone 0.5 0.5 0.5 0.5 Cetyl Dimethicone 0.25 0.25 0.25 0.25 Fragrance 0.05 0.05 0.05 0.05 Silantrol (and) Panthenol — — 2 2 Preservative 0.05 0.05 0.06 0.05 Proliss 100 (50% aqueous) 30 30 30 30 Deionized Water to 100% q.s. q.s. q.s. q.s.

Example 8 Acidic Compositions

AE AF AG AM Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is As Is Citric Acid 0.05 0.05 0.05 0.05 Polyquaternum 67 0.2 0.2 — — PEG-90 M 0.5 0.5 — — Ceteth-2 0.45 0.45 0.45 0.45 Glyceryl Stearate (and) 0.05 0.05 0.05 0.05 PEG-100 Stearate Argan Oil 0.75 0.75 0.75 0.8 Dimethyl Stearamide 0.25 0.25 0.25 0.25 Behentrimonium Methosulfate 0.2 0.2 0.2 0.2 (and) Cetearyl Alcohol Cetyl Alcohol 0.13 0.13 0.13 0.13 Hydrolyzed Keratin 0.1 0.1 0.1 0.1 Soyethyl Morpholinium 0.5 — — — Ethosulfate Cyclomethicone 12.5 12.5 12.5 15 Perfluorononyl Dimethicone 0.5 0.5 0.5 0.5 Cetyl Dimethicone 0.25 0.25 0.25 0.25 Fragrance 1 1 1 1 Silantrol (and) Panthenol 2 2 2 2 Preservative 0.05 0.05 0.05 0.05 Proliss 100 (50%) 30 30 30 37.5 Deionized Water to 100% q.s. q.s. q.s. q.s.

Example 9 Acidic Compositions

AN AQ AR AU Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is As Is Citric Acid 0.05 0.05 0.05 0.05 Ceteth-2 0.45 0.45 0.45 0.45 Glyceryl Stearate (and) 0.05 0.05 0.05 0.05 PEG-100 Stearate Argan Oil 0.8 1 1 0.75 Dimethyl Stearamide 0.25 0.25 0.25 0.25 Behentrimonium Methosulfate 0.2 0.2 0.2 0.2 (and) Cetearyl Alcohol Cetyl Alcohol 0.13 0.13 0.13 0.13 Hydrolyzed Keratin 0.1 0.1 0.1 0.1 Cyclomethicone 15 15 15 15 Perfluorononyl Dimethicone 0.5 0.5 0.5 — Cetyl Dimethicone 0.25 0.25 0.25 — Fragrance 1 1 1 1 Silantrol (and) Panthenol 2 2 2 2 Preservative 0.05 0.05 0.05 0.05 Zinc Nitrate — — 0.2 — Glyoxylic Acid (50% aqueous) — 20 25 — Proliss 100 (50% aqueous) 35 — — 30 Deionized Water to 100% q.s. q.s. q.s. q.s.

Example 10 Acidic Compositions

AV AW AX BA Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is As Is Citric Acid 0.05 0.05 0.05 0.05 Ceteth-2 0.45 0.45 0.45 0.45 Glyceryl Stearate (and) 0.05 0.05 0.05 0.05 PEG-100 Stearate Argan Oil 1 5 4 5 Dimethyl Stearamide 0.25 0.25 0.25 0.25 Behentrimonium Methosulfate 0.4 0.4 0.4 0.4 (and) Cetearyl Alcohol Cetyl Alcohol 0.27 0.27 0.27 0.27 Hydrolyzed Keratin 0.1 0.1 0.1 0.1 Cyclomethicone 15 — — — Perfluorononyl Dimethicone 0.5 0.5 0.5 0.5 Cetyl Dimethicone 0.25 0.25 0.25 0.25 Fragrance 1 1 1 1 Silantrol (and) Panthenol 2 2 2 2 Preservative 0.05 0.05 0.05 0.05 Proliss 100 (50%) 30 30 30 30 Deionized Water to 100% q.s. q.s. q.s. q.s.

Example 11 Acidic Compositions

Wt. % Wt. % Wt. % Wt. % Wt. % Ingredients As Is As Is As Is As Is As Is Wt. % Trade/Common/INCI/Name BB BC BE BF BG As Is B Citric Acid 0.05 0.05 0.05 0.05 0.05 — Ceteth-2 0.45 0.45 0.45 0.45 0.45 — Glyceryl Stearate (and) 0.05 0.05 0.05 0.05 0.05 — PEG-100 Stearate Polyquaternum 67 — — — — — 0.2 Argan Oil 3 2.5 — — — — Shea Butter amidopropyltrimonium — — — — — 0.7 chloride Sunflower Oil — — 2.5 2 1.75 2 Distearyl Stearamide 0.25 0.25 0.25 0.25 0.25 — Behentriomonium Methosulfate (and) 0.4 0.4 0.4 0.4 0.4 0.7 Cetearyl Alcohol Cetyl Alcohol 0.27 0.27 0.27 0.27 0.27 — PEG-90M (and water) — — — — — 2 Hydrodyzed Keratin 0.1 0.1 0.1 0.1 0.1 — Perfluorononyl Dimethicone 0.5 0.5 0.5 0.5 0.5 — Cetyl Dimethicone 0.25 0.25 0.25 0.25 0.25 — Hydrolyzed Wheat Protein (and) — — — — — 2 Methicone (and) Polyquaternum-10 and carbocysteine Fragrance 1 1 1 1 1 0.5 Silantriol (and) Panthenol 2 2 2 2 2 2 Preservative 0.05 0.05 0.05 0.05 0.05 — Proliss 100 (50% aqueous) 30 30 30 30 30 30 Actiphyte of Sunflower Seed BG 50P — — — — 2 2 Deionized Water to 100% q.s. q.s. q.s. q.s. q.s. q.s.

Example 12 Acidic Compositions

AI AJ AK AP Weight Weight Weight Weight Ingredients Percent Percent Percent Percent Trade/Common/INCI/Name As Is As Is As Is As Is Citric Acid 0.05 0.05 0.05 0.05 Ceteth-2 0.45 0.45 0.45 0.45 Glyceryl Stearate (and) 0.05 0.05 0.05 0.05 PEG-100 Stearate Argan Oil 0.75 0.75 0.75 0.8 Dimethyl Stearamide 0.25 0.25 0.25 0.25 Behentrimonium Methosulfate 0.20 0.20 0.20 0.20 (and) Cetearyl Alcohol Cetyl Alcohol 0.13 0.13 0.13 0.13 Hydrolyzed Keratin 0.1 0.1 0.1 0.1 Cyclomethicone 12.5 12.5 15 15 Perfluorononyl Dimethicone 0.5 0.5 0.5 0.5 Cetyl Dimethicone 0.25 0.25 0.25 0.25 Fragrance 1 1 1 1 Silantrol (and) Panthenol 2 2 2 2 Preservative 0.05 0.05 0.05 0.05 Glyoxylic Acid (50% aqueous) — — — 30 Proliss 100 (50% aqueous) 35 40 40 — Deionized Water to 100% q.s. q.s. q.s. q.s. pH 1.5 1.5 1.5 1.5

Example 13 Hair Straightening

This example illustrates the enhanced hair straightening achieved using the Alkaline Composition of Example 5H containing about 0.25 active weight percent sodium hydroxide and the Acidic Compositions of Examples 8AG, 12AI and 12AJ varying respectively in concentration of glyoxylic amide in the range of about 15, about 18 and about 20 active weight percent (Studies A, B, C).

Study A.

Two subjects, one having Type 3A hair and the other having Type 2B hair, received enhanced hair straightening using a half-head comparison in salon studies as described below.

Half-head studies were performed by following the procedure of the hair straightening Method described in section II above, except that the hair was not water rinsed in step 4, so at the end of the 30 minute contact time, the hair was substantially dried as described in step 5 under the hooded dryer. The hair was then center parted from the front to the back of the head for the following half-head comparison.

On the subject having Type 3A hair, the Acidic Composition of Example 8AG was applied to the hair on one side and the Acidic Composition of Example 12AI was applied to the hair on the opposite side. On the subject having Type 2B hair, the Acidic Composition of Example 8AG was applied to the hair on one side and the Acidic Composition of Example 12AJ was applied to the hair on the opposite side.

After about 30 minutes, the hair was blow-dried, pressed with the Flat iron, and water rinsed as described in steps 9-13 and then evaluated for total hair straightening. Step 14 was omitted and the hair was then blow-dried using the fingers and flat ironed using large partings for final styling. The hair was then subjectively evaluated for feel and shine attributes.

On the Type 3A hair, the overall straightening achieved with the Alkaline Composition of Example 5H was judged to be about 36% and the hair on the side straightened with the Acidic Composition of Example 12AI was judged slightly straighter than hair straightened with the Acidic Composition of Example 8AG. On the Type 2B hair, the overall straightening achieved with the Alkaline Composition of Example 5H was judged to be about 12% and the hair on the side straightened with the Acidic Composition of Example 12AJ was judged slightly straighter than the hair straightened with the Acidic Composition of Example 12AJ. Overall, the straightening of both types of hair was judged to be enhanced to about 56%, based on the appearance of the wet hair and enhanced to about 95-98%, based on the appearance of the dry hair.

Study B.

Similar half-head studies were made as in Study A repeating the same general hair straightening procedure on two subjects, one having Type 2B hair and one having Type 3A hair, except that the water rinse in step 4 was carried out, and the Acidic Composition of Example 12AK was compared to the Acidic Composition of Example 8AG.

On the Type 2B hair, the overall straightening achieved with the Alkaline Composition of Example 5H was judged to be about 34% and the hair on the side straightened with the Acidic Composition of Example 12AK was judged slightly straighter than the hair straightened with the Acidic Composition of Example 8AG. On the Type 3A hair, the overall straightening achieved with the Alkaline Composition of Example 5H was judged to be about 62% and the hair on the side straightened with the Acidic Composition of Example 12AK was judged slightly straighter than hair straightened with the Acidic Composition of Example 8AG. Overall, the straightening of both types of hair was judged to be substantially enhanced to about 98-99%, based on the appearance of the hair, wet or dry.

Study C.

The half-head procedure of Study B was repeated on one subject having Type 2B hair, except that Acidic Composition of Example 8AG was compared against the Acidic Composition of Example 8AM (containing about 18.75 active weight percent glyoxylamide). The hair straightening and efficacy was judged equivalent.

Overall, the results showed that the enhanced hair straightening increased slightly more by increasing the glyoxylamide concentration of the Acidic Composition from about 15% to about 18%, but surprisingly, the efficacy achieved with a gloxylamide content of about 18% was judged equivalent to that achieved at glyoxylamide concentrations of about 18.75%.

Example 14 Hair Straightening

This example illustrates the enhanced hair straightening achieved using the Alkaline Composition of Example 1B containing about 0.5 active weight percent sodium hydroxide and the Acidic Compositions of Examples 9AN and 8AM varying respectively in concentration of glyoxylic amide in the range of about 17.5 about 18.75 active weight percent.

One subject having tightly curly hair (Type 3B) hair received enhanced hair straightening using a half-head comparison in a salon study. The procedure of Method II described above was generally followed using the Alkaline Composition of Example 1B in step 4, leaving it in contact with the hair for about 35 minutes to partially straighten the tight curls. The half-head procedure of step 6 was performed by applying the Acidic Composition of Example 9AN to the hair on one side and the Acidic Composition of Example 8AM to the hair on the opposite side.

Surprisingly, the hair on the side straightened with the Acidic Composition of Example 9AN was judge slightly straighter than the hair straightened with Acidic Composition of Example 8AM. Thus, hair straightening efficacy achieved with a glyoxylamide content of about 17.5% was judged slight greater than achieved with a glyoxylamide concentration of about 18.75%.

The straightening achieved on this Type 3B hair with the Alkaline Composition of Example 1B was judged to be about 52%. Overall, the straightening of the hair by the Acidic Compositions was judged to be enhanced to about 79%, based on the appearance of the wet hair and enhanced to about 99%, based on the appearance of the dry hair.

Example 15 Hair Straightening

This example illustrates the enhanced hair straightening achieved using the Alkaline Composition of Example 5H containing about 0.25 active weight percent sodium hydroxide and the Acidic Compositions of Examples 9AQ, 9AR and 12AP varying respectively in concentration of glyoxylic acid in the range of about 10, about 12.5 and about 15 active weight percent, and the Acidic Compositions of Examples 8AG and 9AN, varying respectively in concentration of glyoxylic amide in the range of about 15, and about 17.5 active weight percent.

Three subjects received enhanced hair straightening using a half-head studies (A, B, C) in salon studies generally following the procedure of the hair straightening Method described in II above, except that after step 13, the hair was lightly washed with a commercial shampoo and conditioned for about 3 minutes. In half-head study A, the Acidic Composition of Examples 9AQ was applied to the hair on one side and the Acidic Composition of Example 8AG was applied to the hair on the opposite side. In half-head study B, the Acidic Composition of Example 9AQ was applied to the hair on one side and the Acidic Composition of Example 8AG was applied to the hair on the opposite side. In half-head study C, the Acidic Composition of Example 9AN was applied to the hair on one side and the Acidic Composition of Example 12AP was applied to the hair on the opposite side. The hair straightening achieved was assessed visually by professional beauticians experienced in the art of hair straightening.

In each of the half-head studies, the straightened hair was judged equally soft and silky on both sides. In half-head study A, the straightening achieved was judged to be about 85% on both sides; in the half-head study B, the straightening achieved was judged to be about 85% on the side straightened with glyoxylic amide and about 80% on the side straightened with glyoxylic acid; and in half-head study C, the straightening achieved was judged to be about 75% on both sides.

Example 16 Hair Straightening

This example illustrates the enhanced hair straightening achieved using the Alkaline Composition of Example 5H containing about 0.25 active weight percent sodium hydroxide and the Acidic Composition of Example 8AG containing about 15 active weight percent of glyoxylic amide on Type 2C hair that had been previously colored and bleached. The general procedure of Method II was followed, except that in step 12, the hair was water-rinsed for about three minutes, then gently washed with shampoo, conditioned with commercial hair conditioner for about three minutes and then washed with water. The hair was judged very straight, very silky in feel, and very shiny.

The tensile strength of the hair was analyzed by the Intermittent Stress Relaxation Method (ISR) procedure described in section I above. The ISR index of the straightened hair was 0.79 relative to that of the hair before straightening normalized to 1, indicating a loss in elasticity of about 21%.

Similar hair straightening procedures as above were performed on Type 2 hair that had been previously bleached and colored, except that the alkaline compositions of Examples 2B, and 2E comprising triethanolamine as the chemical base and using the alkaline compositions of Example 5D comprising sodium carbonate were used.

Overall, the hair was judged to be significantly straightened (more than about 75%), soft and silky in feel, and very shiny.

Example 17 Hair Straightening

Hair that was classified as resistant Type 3B/3C was successfully straightened by the hair straightening Method II using the Alkaline Composition of Example 1A comprising about 1 active weight percent sodium hydroxide for about 10 minutes in step 4, and an Acidic Composition of Example 7U. The straightening achieved with the Alkaline Composition was judged at about 22% and was enhanced to about 87% by the Acidic Composition with an overall straightening effect of about 97% when the hair was dry.

In a similar study on Type 3B/3C hair using the Alkaline Composition of Example 1A for about 22 minutes in step 4, and an Acidic Composition of Example 7Y. The straightening achieved with the Alkaline Composition was judged at about 44% and was enhanced to about 99% by the Acidic Composition overall.

Overall, the results show that the enhanced hair straightening system of this invention can be used to effectively remove substantially all the natural curl in the hair, especially hair that is generally recognized as being resistant. Straightening effects are achieved that are long lasting (at least 3 to 4 months), and the hair surprisingly retains desirable sensory and aesthetic attributes of hair, such as strength, or soft, silky feel, and high sheen.

The foregoing Examples are intended to be illustrative and not limiting. Numerous variations and modifications may be effect without departing from the true spirit and scope of the invention. 

1. (canceled)
 2. The method of claim 15 wherein the alkaline composition comprises a sufficient amount of chemical base to maintain a pH of at least 9.5 during step (a).
 3. The method of claim 15, wherein the chemical base in the alkaline composition comprises at least one compound selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, an organic amine, and alkaline salts thereof.
 4. The method of claim 3, wherein the chemical base in the alkaline composition comprises at least one alkali metal hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide.
 5. The method of claim 3, wherein the chemical base in the alkaline composition comprises calcium hydroxide.
 6. The method of claim 15, wherein the chemical base in the alkaline composition comprises at least one organic amine selected from the group consisting of guanidine, guanidine hydroxide, and a C₁-C₆ alkanolamine.
 7. The method of claim 3, wherein the chemical base in the alkaline composition comprises at least one salt selected from the group consisting of guanidine carbonate, sodium carbonate, and sodium phosphate.
 8. The method of claim 15, wherein the acidic composition comprises at least one glyoxylic amide selected from the group consisting of N-glyoxylcarbocysteine, N-glyoxylderivatives of keratin amino acids and mixtures thereof.
 9. The method of claim 17, wherein the oxidizing agent in the hair conditioning composition in step (i), when present, is selected from the group consisting of hydrogen peroxide and sodium bromate. 10-14. (canceled)
 15. A method of enhancing the removal of the natural curl from hair having a visibly wavy to tight curly configuration, the method comprising the steps of: (a) contacting naturally wavy, curly hair with an alkaline composition comprising a sufficient amount of chemical base to provide alkalinity in the range of at least pH 8.5 to about pH 14 for a period sufficient to partially straighten the original configuration of the hair; (b) optionally washing the partially straightened hair; (c) drying the partially straightened hair to a substantially dry state, optionally with a hair conditioning composition on the hair; (d) contacting the so-dried, partially straightened hair with an acidic composition having an acidity of less than about pH 2.5, the acidic composition comprising at least one compound selected from the group consisting of glyoxylic acid, a glyoxylic amide, and a mixture thereof, in a cosmetically acceptable vehicle and present in an amount sufficient to further straighten the configuration of the hair; (e) optionally heating the hair in step (d) for a period of up to about 30 minutes; (f) optionally washing the further straightened hair; (g) drying the further straightened hair to a substantially dried state; and (h) pressing the substantially dried straightened hair with a heated iron.
 16. The method of claim 15, wherein the hair is covered with a cap during step (e), the cap being removed before steps (f) and (g).
 17. The method of claim 15, further including the steps of: (i) washing the pressed, straightened hair with water after step (h), and optionally contacting the washed hair with a hair conditioning composition comprising an oxidizing agent, and optionally, washing the conditioned hair with water; (j) blow drying the hair after step (i) optionally with a thermal protectant composition present on the hair; and (k) pressing the blow-dried hair with a heated iron, optionally with a hair conditioning composition on the hair.
 18. The method of claim 17, wherein the chemical base in the alkaline composition comprises at least one compound selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, an organic amine, and alkaline salts thereof.
 19. The method of claim 17, wherein the chemical base in the alkaline composition comprises at least one alkali metal hydroxide selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide.
 20. The method of claim 17, wherein the chemical base in the alkaline composition comprises calcium hydroxide.
 21. The method of claim 17, wherein the chemical base in the alkaline composition comprises at least one organic amine selected from the group consisting of guanidine, guanidine hydroxide, and a C₁-C₆ alkanolamine.
 22. The method of claim 17, wherein the chemical base in the alkaline composition comprises at least one salt selected from the group consisting of guanidine carbonate, sodium carbonate, and sodium phosphate.
 23. The method of claim 17, wherein the acidic composition comprises at least one glyoxylic amide selected from the group consisting of N-glyoxylcarbocysteine, N-glyoxylderivatives of keratin amino acids and mixtures thereof.
 24. The method of claim 15 wherein the chemical base in the alkaline composition comprises calcium hydroxide, guanidine carbonate, and a mixture thereof.
 25. The method of claim 15, wherein the alkaline composition comprises guanidine hydroxide and the acidic composition comprises N-glyoxylcarbocysteine, N-glyoxylderivatives of keratin amino acids, and a mixture thereof.
 26. An article of manufacture in the form of a kit containing the following components for practicing the method of claim 15, each in separately packaged form: an alkaline composition comprising at least one chemical base selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, an organic amine, and alkaline salts thereof in an amount sufficient to provide alkalinity in the range of at least pH 8.5 to about pH 14; an acidic composition having an acidity of less than about pH 2.5, the acidic composition comprising at least one compound selected from the group consisting of glyoxylic acid, a glyoxylic amide, and a mixture thereof, in a cosmetically acceptable vehicle; and optionally a hair conditioning composition; instructional indicia on how to use the components during the method for enhancing the removal of the natural curl from hair having a visibly wavy to tight curly configuration; and optionally, one or more hair straightening implements. 